Tritanopia: Blue-Yellow Color Blindness

What is Tritanopia?

Tritanopia is a rare type of genetic color blindness that affects a person’s ability to distinguish between the colors blue and yellow. About 1 in 15,000 newborns are born with tritanopia, and males and females are equally affected.¹

The retina (layer in the back of the eye that sends light signals to the brain) is responsible for our ability to see color. Three types of cone cells in the retina detect color: red, green, and blue. 

Tritanopia occurs when the blue-sensitive cones, also called short-wavelength cones (S cones) in the retina, are not functioning or completely missing. This results in difficulty distinguishing colors. 

While tritanopia changes a person’s color perception, it does not affect normal vision or visual acuity. Tritanomaly is a milder form of tritanopia.

Symptoms of Tritanopia

Color vision deficiency ranges from mild to severe. People with mild color blindness may not be aware they have it. Some school-aged children are diagnosed when they have trouble learning colors. 

People with tritanopia have trouble distinguishing specific colors. 

Symptoms include:

• Blues appear green
• Yellows and oranges appear pink
• Purples appear deep red
• Trouble seeing brightness in the usual way
• Inability to distinguish the difference between shades of the same color 

The most common form of color vision deficiency is red-green dichromacy, resulting in difficulty seeing traffic lights. People with tritanopia typically don’t have trouble distinguishing between red and green lights.

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Tritanopia: Blue-Yellow Color Blindness

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What Causes Blue-Yellow Color Blindness?

Tritanopia, also called blue-yellow color blindness, is usually caused by a genetic mutation and is present at birth. Since the mutation is not sex-linked, it affects males and females similarly. 

Tritanopia can also be the result of an injury and certain medical conditions, including:

• Blunt trauma to the eye
• Exposure to ultraviolet light
• Macular degeneration 
• Diabetes
• Cataracts
• Alcoholism
• Exposure to certain organic solvents 
• Certain medications, including chloroquine (treats malaria and arthritis)

Caucasian males are typically at a higher risk for color vision deficiencies. 

How is Tritanopia Diagnosed?

Eyecare professionals screen for tritanopia using the Hardy Rand Rittler test. 

Other exams that test for color deficiency include:

• Ishihara test. Uses dots and colors to screen for red-green color defects
• Anomaloscope test. Checks to see if you can match the brightness of two lights
• Hue test. Consists of arranging colored blocks in rainbow order
• Farnsworth Lantern test. Quickly displays two colors at a time (used on pilots)

How is Tritanopia Treated? 

While there is no cure for tritanopia or color blindness, color deficiencies can be treated with special visual aid devices and technology. 

The Color Correction System applies filters to glasses and contact lenses, allowing people to see color. 

Glasses 

Several companies have advanced in treating color vision deficiencies with state-of-the-art lens technology integrated into color blind glasses.

EnChroma glasses use optical lens technology to filter light wavelengths at the precise point in the retinal cone cells where the overlap of color deficiency occurs. This technology allows people to see contrast and more vibrant colors. However, EnChroma glasses are only for people with red-green color blindness, not tritanopia. 

Pilestone’s Lens E color blind glasses are specifically designed for people with tritanopia. Like EnChroma, Pilestone glasses manipulate light wavelengths at the point where cone cells overlap, making it easier for the brain to differentiate colors. 

Colorblind glasses look similar to sunglasses and can be customized to fit your prescription. They only work while wearing them.   

Contacts Lenses

Contact lenses are an option for people with red-green color deficiencies. Special contact lenses are designed to help people distinguish colors.

Currently, there are not any contact lenses designed for people with tritanopia. 

Visual Aids

Many digital visual aids are available to help correct color blindness. Popular computer-based programs include:

• Apps that tell you the color of images
• Tools that highlight specific colors within a different color
• Patterns to highlight specific color tints

Living With Tritanopia

Living with tritanopia can be frustrating and make specific daily tasks difficult, including shopping, cooking, and driving. Color blindness can also limit your ability to work in certain professions that require the correct identification of colors (graphic designer, pilot).

However, having a color deficiency will not alter your normal vision, and there are several ways to adapt and manage color vision deficiencies. 

A few tips on how to effectively cope and live with tritanopia include:

• Have someone help you label and organize clothes by color
• Memorize specific colors that are found in everyday items
• Use bright lighting around your home
• Let teachers and employers know you are color blind so they can accommodate you
• Adjust the lighting on computers and digital devices for easier use

If you notice a change in the way you perceive color or a difference in your vision, it is essential to see an ophthalmologist for further testing. 

Summary

Tritanopia is a rare type of color blindness that alters how you see the colors blue and yellow. It is caused by the absence of S cone cells (short wavelength) in the retina and is typically the result of a gene mutation. 

While there is no cure for color vision deficiencies, specific tools can help distinguish colors and see contrast, including special glasses, contact lenses, and visual aids. Many adapt and learn to live with color blindness by using organization, memorization, and bright lighting strategies.